Automatic piano



Nov. 5, 1929. J. HjmcKlNsoN 1,734,717

AUTOMATI O PIANO Filed Dec. 22. 1922 2 sheets-sheet 1 XII/4 06 75ATTORNEY 7 I I lfENTOR I w'om 1929- I J. H. DICKINSCN 1,734,717

AUTOMATIC PIANO Filed Dec. 22. 1922 2 Sheets-Sheet 2 INVEVTOR PatentedNov. 5, 1929 UNITED STATES PATENT OFFICE,

J'OSEPH HUNTER DICKINSON, OF LARCHMONT, NEW YORK, ASSIGNOR TO THEAEOLIAN COMPANY, A CORPORATION OF CONNECTICUT AUTOMATIC PIANOApplication filed December 22, 1922. Serial No. 608,524.

My present invention relates to improvements in automatic players,includin'gthe socalled reproducing piano, which reproduces the loud andsoft expression or dynamic effects of the artist automatically from themusic-roll. The means by which I accomplish this is eliective and at thesame time relatively simple to manufacture, adjust and keep in order.Said means, embodied in what I have hereinafter called anexpression-box, may take a variety of forms, that shown being theembodiment which at present I prefer.

In the drawings, Fi 1 is a longitudinal, vertical cross-sectional viewof my improved expression-box in Combination with the related parts ofan automatic or player plano, the latter and the interconnections beingsu'liiciently shown in a merely diagrammatic manner; Fig. 2 is a partialview in plan of the tracker bar of Fig. 1 and the music-sheet; Fig. 8 isa transverse section, partly in elevation, of the valve-box on any ofthe l1nes 8-3 in Fig. 1 looking in the direction of the :5 arrows; Figs.4, 5 and 6 relate to the expression-box and are transverse sectionalviews,

partly in elevation, on the lines 4-4, 5 5

and 66, respectively in Fig. 1, looking in the direction of the arrows,and Fig. 7 is an enlarged sectional view partly in elevation on the line7-7 in Fig. 1 looking in the direction of the arrows.

Describing now my invention in its setting as shown in the drawings, 1is the tracker-bar having expression controlling ducts 2 andnote-playing ducts 3, of which latter only a few are shown. 4 is theperforated music-sheet having expression controlling perforations 5 andnote-playing perforations 6.

7 designates collectively thewell-known v parts of one of the hammeractions of the piano; 8 is the related piano string; and 9 designatescollectively a well-known form of valve controlled striker pneumaticaction, one for each hammer action of the piano to ac tuate same, saidvalve being itself controlled in well-known manner from thecorresponding note-playing duct 3 of the tracker bar through thediagrammaticallyshown tube connection 10 so that when said tracker ductis closed by the musicsheet, the striker pneumatic is connected with theatmosphere and is expanded and quiescent, whereas when it is opened bythe note-playing perforations of the sheet, saidpneumatic is cut offfrom the atmosphere and connected through the diagrammatically showntube 11 with the ex hauster through the expression-means (next to bedescribed) and is collapsed and operates the hammer action to strike thepiano string and sound the given note.

The force with which the striker pneumatics propel the hammers isdetermined by the aforesaid expressionbox which in the preferred formshown comprises the following: 12 is a chamber connected with thestriker pneumatic action by the aforesaid tube 11, and 13 is a secondchamber connected through opening 14c with the exhauster. These chambersare connected with each other by a plurality of ports through thepartition separating the two chambers. These ports are designated in thedrawings FF (meaning fortissimo), F (forte), MF (mezzo-forte), and P(piano), and PP (pianissimo) because when the FF port, for example, isopen it connects the full, untempered exhaust with the striker pneumaticaction and the playing is therefore fortissimo; similarly, opening theport F makes the playing forte, and so on with the other ports inaccordance with their designations.

Said orts respectively have valves as follows: The valve of the port FFconsists of a leather faced disk 15 whose foot 16 is glued to the pouch17 ofa pouch chamber 18 connected to one of the expression control ductsin the tracker bar through any usual and well known valve means 19(Figs. 3 and 1) whereby as long as said duct is closed by themusic-sheet the aforesaid pouch-chamber 18 is connected with theatmosphere and has its pouch expanded, holding the valve closed againstthe port FF. Vice versa, as soon as an expression controllingperforation in the music-sheet opens said tracker duct, then the actionof the valve means is reversed in well known manner, disconnecting theafore said pouch-chamber from the atmosphere for operation.

and connecting it with the exhaust so that the pouch collapses and pullsthe valve away from the port FF, and thereby throws the full exhaust onthe striker pneumatic action for fortissimo playing.

The valve is guided in its movement to and away from its port FF by fourequally spaced pins surrounding it, only two of which, are shown in thedrawings.

The valves of the ports F, MF and P, the guide pins, and the operatingpouches are all the same as just described in. connection with the portFF, the only differences being that the valves for the ports F, MF and Pare not glued or otherwise secured to their respective pouches; andfurthermore are yieldingly held toward their ports by tension springs22.

The respective pouch-chambers for the ports F, MF and P are operativelyconnected with the expression controlling tracker bar ducts 21, throughthe valve means 19 in an exactly similar way to that described inconnection with the pouelrchamber 18 for the port FF, it beingunderstood that each of said pouch-chambers for FF, F, MF and P isthereby connected through it own valve means with its own expressioncontrolling tracker duct for independent operation and control from themusic-sheet expression con trolling perforations.

The aforesaid tension springs 22 for the Valves of the ports F, MF andPPP are large diameter coiled springs which connect eyes 23 onthe valveswith eyes on the ends of threaded rods 24 passing through holes in thecover of the chamber where they are each provided with a leather washerand nut.

The'design and adjustment of these springs is such that the spring for Fis weakest, that for MFis stronger, that for P is stronger still, andthat for the valve controlling the port PP is strongest of all.

The valve for the last named port PP dif fersfrom the others in nothaving any foot portion or any pouch chamber for operating it. Thus,this is the only valve of the series which is not controllable from themusic-sheet but on the contrary is always normally ready This means thatthe instrumentplays normally soft when none of the expression ducts inthe tracker bar is open.

The operation is as follows: \Vhen the exhauster is in operation withthe music-sheet travelling across the tracker bar, all noteplayingperforations registering with the tracker bar ducts will sound theirnotes pianissimo if they have no expression controlling perforationsadjacent their front ends in the music-sheet. This will be so because,when there are no expression controlling perforations, the music-sheetwill seal all four of the expression ducts of the tracker bar.Therefore, all'of the valves 33 will be downso to admit atmosphere toallof the pouch chambers 18 which will, therefore, be expanded as shown inthe drawings, causing their controlled valves to be seated positivelyagainst all the ports FF, F, MF and P. Therefore, the air from thestriker pneumatic action must exhaust through the port PP past the valveof said port. But this is the valve having the strongest spring tensionagainst opening and therefore all striker pneumatics in operation atthis time will collapse with minimum force and operate their hammeractions pianissimo.

All succeeding music perforations will continue to play pianissimo untilan expression controlling perforation uncovers one of the expressioncontrolling tracker ducts 2. If this uncovered tracker duct be the onecon nected with the pouch chamber of the port P, then the uncovering ofsaid tracker duct will operate the related valve means 33 in well knownmanner to cut off the atmosphere from said pouch chamber and to connectthe exhaust therewith, whereupon said pouch will collapse and leave thevalve of said port P free to operate. This valve having a weaker springtension than the valve of the port PP, the air from the strikerpneumatic action will now exhaust through port P by opening its valveagainst said weaker spring tension. Therefore, the striker pneumaticsthen in play will sound their notes piano or somewhat louder than theplaying when the exhaust took place through the port PP.

In exactly the same way, if an expression controlling perforation in themusic-sheet uncovers the tracker duct connected with the pouch chamberof the port M'F, then said pouch will collapse and release the valve ofsaid port MF into action, and because this valve has only a mezzo-fortespring tension, which is less-than the tension of the valves on theports P and PP, the air from the striker pneumatics will be exhaustedonly past said MF valve and the playing of the striker pneumatics thenin action will be mezzo-forte.

The same applies to an uncovering of the tracker duct connected with thepouch chamber of the port F. Releasing into action of the valve of thisport causes the air from the striker pneumatic action to exhaust pastthe valve of this port and to play forte because its spring tension isthe weakest of all.

The valve controlling the port FF has no spring opposing its openingand, therefore, when its pouch chamber is collapsed by an expressioncontrolling perforation in the musicsheet registering with the relatedtracker duct, said valve is completely unseated from the port FF and thefull exhaust acts directly on the striker pneuinatics then in play,causing them tosound their notes fortissiino.

The coils of the tension springs are purposely made large in diameterbecause I have discovered that by so doing I can make the tensionedvalves maintain thegiven degree of loudness or softness unchangedirrespective of thefnumber of striker pneumatics in action, whether oneonly or any increased number up to the maximum ordinarily required to beoperated simultaneously I in reproducing hand-played pianofortecompositions. When many striker pneumatics are in simultaneous action atPP, P, MF, etc., it means that pro portionately more air mustbe passedby the given valve than'if only one striker pneumatic werein action.'This in turn means that the given valve must momentarily move furtheraway fromits port PP or P, etc., but this would increase the tension ofthe springs and change the dynamics of the playing if the coils weresmall in diameter instead of relatively large, as I make them. In short,the advantage of the large diameter springs is that they do notsubstantially change their tension on the valves when the latter open toa greater or less distance to accommodate for the passing of a greateror less volume of air according to the number of striker pneumatics insimultaneous action.

The valve means 19 heretofore referred to between the expressioncontrolling tracker ducts and the pouch chambers of the valvescontrolling the ports P, MF, F and FF, be ing so well known in this artneed not be described. However, for those not skilled in the art it maybe briefly said to'comprise four valve units. all alike, mounted in abox as shown in Fig. 1 (plan view) and Fig. 3 (transverse'section). Thechamber within the box is permanentl connected with the exhauster. 2G-26are saucer-shaped metal members mounted as shown in pairs in the mouthsof holes through the top of the valve box. The bottom of eachsaucer-shaped member has a hole or port through it which alines with theport through the other member of the pair. The upper ports 31 connectwith the atmosphere and the lower ports 32 with the exhaust in thechamber.

For each pair of ports there is a valve 33 located between said ports ona valve stem .84 having a foot portion resting on a pouch covering achamber 36 in the bottom board of the box. Each of said pouch chambersis connected by a duct 37 and a tube 88 with one of the expressioncontrolling tracker bar ducts. Each is also permanently connected wiihthe exhaust chamber by a small so-called bleed opening 40. Each hole 30through the top board between the ported members 2626 is connected by aduct 39 and a tube 21 with one of the pouch chambers 18 controlling thevalve of one of the ports P, MF, F or FF.

The operation of the described valve means is well understood by thoseskilled in the art. The exhaust in the chamber 25 acting through thebleeds 4:0 exhausts the pouch chambers 36, the ducts 37 and the tubes38. This is their normal condition while the music-sheet seals theexpression controlling tracker ducts. The

pouches are therefore collapsed with the valves 33 sealing the exhaustports 32 and opening the atmosphere ports 31 so that atmosphere is onthe pouch chambers 18 re lated to the ports P, MF, F and FF of theexpression box, keeping said pouches raised as shown in Fig. 1.

Should now an expression controlling perforation or perforations in themusic-sheet uncover one or more of the expression tracker bar. ducts,then atmosphere will rush into the given tube 38, duct 37, and pouchchamber 36 and will lift said pouch and its valve, thereby sealing thelatter against its atmosphere port and opening its exhaust port 32 sothat now the related pouch chamber in the expression box is connectedwith the exhaust and its pouch therefore collapses, and depending uponwhich pouch chamber is connected, either releases for action the valveor valves of the related ports P, MF, F or opens the valve of the portFF.

The expression means has been so far described as being controlledautomatically from the music-sheet but it can also be manuallycontrolled. One form of said manual means is shown in plan view at L1 inFig. 1 and in section in Fig. 7. The device comprises a block havingducts 42 connected by tubes 143 respectively with the tubes 38, saidducts at their other ends opening through the bottom of the block asshown in Fig. 7. The ports thus formed are kept normally closed byvalves 43 on leaf-springs 44 secured at 4.5 to the block. Each of thefour leaf-springs has an attached button 46 which projects loosely upthrough a hole in the block. Thus, the operator can manually depress anyof these buttons 46 at will to open the corresponding valve 43 and duct42 so that atmosphere will be admitted to the corresponding tube 38Fig. 1) with the same operative consequences as if the correspondingexpression tracker duct had been opened by an expression perforation 5of the music-sheet.

hat I claim is:

1. In combination with the tracker bar, the striker-pneumatic action andthe exhauster of an automatic piano, an expressionmeans comprising twononcollapsible chambers respectively connected with the strikerpneumaticaction and the exhauster, said chambers being connected by a pluralityof ports, valves for said ports in the chamber connected with theexhauster, and springs having graded tensions arranged to actuate saidvalves yieldingly to said ports.

2. In combination with the tracker bar, the striker-pneumatic action andthe exhaust-er of an automatic piano, an expression-means comprising twonon-collapsible chambers respectively connected with thestriker-pneumatic action and the exhauster, said chambers beingconnected by a plurality of ports, valves for said ports in the chamberconnected with the exhau'ster', springs having graded tensions arrangedto actuate said valves yieldingly to said ports, and means forindividually controlling said valves to put same into and out of action.

3. In combination with the tracker bar, the striker-pneumatic action andthe exhauster o1 an automatic piano, an expression-box comprising twonon-collapsible chambers respectively connected with thestriker-pneuinatic action and the exhauster, said chambers beingconnected by a plurality of ports, valves for said ports in the chamberconnected with the exhauster; and means for yieldingly actuating saidvalves to said ports with different pressures for the difierent valves.

l In combination with the tracker bar, the striker-pneumatic action andthe exhauster of an automatic piano, an expressionbox comprising twonon-collapsible chambers respectively connected with thestriker-pneumatic action and the exhauster, said chambers beingconnected by a plurality of ports, valves for said ports in the chamberconnected with the exhauster; and means for yieldingly actuating saidvalves to said ports with d1 r'erent pressures for the different valves,and means for individually controlling said valves to put same into andout of action.

5. In combination with the tracker bar, the strikerpneumatic action andthe exhauster 01" an automatic piano, an expression-box comprising twonon-collapsible chambers respectively connected with thestriker-pneuniatic action and the enhauster, said chambers beingconnected by a port; a valve for said port in the chamber connected withthe exhauster; a spring arranged to actuate said valve yieldingly to itsport; and means for controlling said valve to put it into and out ofaction.

6. In combination with the tracker bar, the striker-pneumatic action andthe exhauster of an automatic piano, an expressionmeans comprising twonon-collapsible chambers respectively connected with thestrikerpneumatic action and the exhauster, said chambers being connectedby a port; a valve for said port in the chamber connected with theexhauster; a coiled spring arranged to actuate said valve yieldingly toits port, the diameter of said spring being relatively large so that itstension does not substantially change with the valve opening a greateror less distance regardless of the number of striker-pneumatics normallyin action; and.

means for controlling said valve to put it into and out of action.

7. In combination with the tracker bar,. the striker-pneumatic actionand the exhauster of an automatic piano, an expression-box comprisingtwo non-collapsible chambers respectively connected with thestriker-pneumatic action and the exhauster, said chambers beingconnected by a plurality of ports, a valve from one of said portscontrolled from the tracker bar for connecting the exhauster directlywith the striker-pneumatic action for loud playing, graded springtensioned valves for the rest of said ports in the chamber con nectedwith the exhauster, and means for selectively controlling said valves toput same into and out of action with the exception of one valve havingthe strongest spring tension which is not so controlled and is alwaysready for action.

8. In combination with the tracker bar, the striker-pneumatic action andthe exhauster of an automatic piano, an expression-means comprising twonon-collapsible chambers respectively connected with thestriker-pneumatic action and the exhauster, said chambers beingconnected by a port; avalve for said port; a coiled spring arranged toactuate said valve yieldingly to its port, the diameter of said springbeing relatively large so that it's tension does not substantiallychange with the valve opening a greater or less distance regardless ofthe number of striker-pneuniatics normally in action.

9. In combination with the tracker bar, the striker-pneumatic action andthe exhauster of an automatic piano, an expression-box comprising twonon-collapsible chambers respectively connected with thestriker-pneuniatic action and the eXha'uster, said chambers beingconnected by a port a valve for said port; means for yieldinglyactuating said valve to its port; and means for controlling said valveto put it into and out of action.

In: testimony whereof, I have signed my name to this specification, this20th day of December, 1922.

JOSEPH HUNTER DICKINSON.

